1. Field of the Invention
The present invention relates generally to an apparatus for controlling the inflation of pneumatic tires. Specifically, it relates to a system which regulates the inflation of pneumatic tires by controlling the duration of each inflation period, providing a pressure reading after each inflation period and checking for over inflation after each period, preventing an additional inflation period without manual intervention, and initiating a further inflation/pressure reading cycle upon release and reengagement of an activating member.
2. Description of the Prior Art
Many tire changers include air inflation systems for inflating pneumatic tires which they process. Preferably, these systems should inflate the tires to the desired pressure level quickly. Compressible fluids such as air can store a substantial amount of energy which releases in a destructive manner upon rupture of the vessel which contains them. Utilizing a substantial pressure differential between the fluid source and the tire or other vessel being charged increases the speed of charging but may also increase the potential energy stored in the system.
One prior method for inflating pneumatic tires includes using an air chuck and a visual pressure meter to perform alternate inflating and measuring steps and, if necessary, alternate bleeding and measuring steps until the air pressure in the tire reaches a desired level. However, this method lacks the accuracy in many modern applications. It also requires that the operator exert a great deal of effort and attention to properly perform the procedure.
The prior art also includes complex electrical control systems which automatically perform the procedure outlined in the previous paragraph. But these systems are unsuitable for the environment under which they must operate. Furthermore, these systems are costly to manufacture and repair. Other prior systems practice procedures with alternating inflating and measuring cycles, but they automatically continue to repeat these cycles. Thus, the operator may unintentionally inflate to a hazardous level.
The improved regulating system of the present invention avoids the problems of the prior art regulating systems. It inflates pneumatic tires with manually initiated cycles of alternate inflating and measuring steps and provides increased safety by requiring repeated manual intervention during the inflation cycle series. It provides a construction which minimizes the expense of manufacture and assembly and allows the operator to quickly and safely inflate a pneumatic tire to a desired pressure level using optimum differential pressures with optimum safety.